Immobilization of organic species on refractory inorganic oxides

Abstract

A broad variety of modified inorganic oxides may be prepared by surface-metallating the oxide with a metal tetrahalide followed by displacement of a halogen bonded to the metal by a nucleophilic organic functional group. The results are organic moieties coating the surface of the oxide by being covalently bonded to a metal which, in turn, is covalently bonded to an oxygen originally associated with a surface hydroxyl of the inorganic oxide.

What is claimed is: 
     
       1. A method of preparing a modified refractory inorganic oxide comprising reacting the surface hydroxyl groups of a porous refractory inorganic oxide selected from the group consisting of alumina, silica, thoria, titania, magnesia, and combinations thereof with a tetrahalide of an element selected from the group consisting of titanium, zirconium, hafnium, vanadium, tantalum, niobium, germanium, tin, lead, and combinations thereof so as to produce a surface-metallated inorganic oxide, removing excess and unreacted metal tetrahalide, heating the metal inorganic oxide at a temperature from about 80° to about 200° C. in an inert atmosphere for a time sufficient to volatilize any remaining unreacted metal tetrahalide, reacting the resulting material with an organic reagent having at least one functional group selected from the group consisting of hydroxyl, amino, sulfhydryl, and phosphino moieties, or with RY where R is a hydrocarbyl moiety and Y is an alkali metal, removing excess adhering but unreacted reagent, and recovering the resulting modified refractory inorganic oxide. 
     
     
       2. The method of claim 1 where the inorganic oxide is alumina. 
     
     
       3. The method of claim 1 where the inorganic oxide is silica. 
     
     
       4. The method of claim 1 where the tetrahalide is a tetrachloride. 
     
     
       5. The method of claim 1 where the metal is titanium. 
     
     
       6. The method of claim 1 where the metal is zirconium. 
     
     
       7. The method of claim 1 where the metal is vanadium. 
     
     
       8. The method fo claim 1 where the reagent has a hydroxyl group. 
     
     
       9. The method of claim 8 where the reagent is a hydroxy carboxylic acid or a hydroxy amine. 
     
     
       10. The method of claim 1 where the reagent has an amino group. 
     
     
       11. The method of claim 10 where the reagent is an amino carboxylic acid or a polyamine. 
     
     
       12. The method of claim 1 where RY is an alkyl or aryl lithium. 
     
     
       13. The product made by the method of claim 1. 
     
     
       14. The product of claim 13 where the inorganic oxide is alumina. 
     
     
       15. The product of claim 13 where the inorganic oxide is silica. 
     
     
       16. The product of claim 13 where the tetrahalide is the tetrachloride of titanium, zirconium, or vanadium. 
     
     
       17. The product of claim 13 where the reagent has an hydroxyl group. 
     
     
       18. The product of claim 13 where the reagent has an amino group. 
     
     
       19. The product of claim 13 where the reagent is a hydroxy carboxylic acid, amino carboxylic acid, hydroxy amine, or polyamine. 
     
     
       20. The product of claim 13 where RY is an alkyl or aryl lithium.